CVE-2026-25835

/* * Conceptual PoC for CVE-2026-25835 (PRNG Seed Misuse) * This demonstrates how a weak or predictable seed compromises the RNG. */ #include <stdio.h> #include <stdlib.h> void simulate_vulnerable_rng(unsigned int seed) { printf("[+] Initializing PRNG with seed: %u\n", seed); srand(seed); // Generate a token that should be random int secure_token = rand(); printf("[+] Generated 'Secure' Token: %d\n", secure_token); } void attacker_predict(unsigned int guessed_seed) { printf("[!] Attacker guessing seed: %u\n", guessed_seed); srand(guessed_seed); int predicted_token = rand(); printf("[!] Attacker predicted Token: %d\n", predicted_token); } int main() { // Scenario: The application uses a predictable seed (e.g., timestamp or PID) unsigned int predictable_seed = 16250; // Example weak seed // Victim execution simulate_vulnerable_rng(predictable_seed); // Attacker execution (knowing the seed logic) attacker_predict(predictable_seed); return 0; }

{"cve": {"id": "CVE-2026-25835", "sourceIdentifier": "[email protected]", "published": "2026-04-01T19:16:28.663", "lastModified": "2026-04-06T14:29:47.000", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Mbed TLS before 3.6.6 and TF-PSA-Crypto before 1.1.0 misuse seeds in a Pseudo-Random Number Generator (PRNG)."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "baseScore": 7.7, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.5, "impactScore": 5.2}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-335"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.18.0", "versionEndExcluding": "3.6.6", "matchCriteriaId": "F718023A-E632-45A1-8C51-781C969DA96D"}, {"vulnerable": true, "criteria": "cpe:2.3:a:arm:mbed_tls:4.0.0:*:*:*:*:*:*:*", "matchCriteriaId": "8EF688FA-732F-4EAF-BAC6-AC3CDAF19588"}, {"vulnerable": true, "criteria": "cpe:2.3:a:arm:tf-psa-crypto:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.1.0", "matchCriteriaId": "7F85529C-03C6-44F4-9242-372DCDF0B52C"}]}]}], "references": [{"url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-rng-cloning/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}